Hair-cutting device



A. VAN DAM ETAL MIR-CUTTING- DEVICE May 19, 1942.

Filed Nov. 7, 1939 Patents May 19, 1942 HMR-CENG DEVECE Alexis van Dam and Ale xandre Horowitz, Eind Application November 7 In Germany N Claims.-

The present invention, which is a continuation-in-part of our U. S. application Serial No. 276,746 filed May 31, 1939, relates to hair-cutting devices and more particularly to electricallydriven razors comprising a cutting head having an apertured cutting or shear plate and a rotatable cutter.

The razors of the type described in our abovementioned application comprise a shear plate provided with radial or substantially radial slits and preferably with a central cavity through the wall of which these slits extend. A rotary cutter cooperates with this ate which is stationary with respect to the razor.

Because of the radial arrangement of the slits it is desired to give the shear plate a rotary manual movement when shaving. Such a movement of the razor during shaving is a disadvantage, particularly to a nevhuser, and if it is not employed the shaving requires more time or is not entirely satisfactory.

The main object of our invention is to overcome the above disadvantage and for this purpose we move the shear plate with respect to the cutter and at a considerably lower speed. For example, we provide means to rotate the shear plate in a direction opposite to that of the cutter and at a speed which is low with respect to that of the cutter, for example, at a speed of from about 40 to 120 revolutions per minute.

We have found that, regardless of the manual movement of the razor, shaving can be effected better and more quickly with a razor according to the invention than with a razor having a stationary shear plate. Furthermore, it is unnecessary to give the razor according to the invention a rotary movement, and entirely satisfactory results are obtained when the razor is moved in 'any manner over the surface to be shaved.

In order that the invention may be clearly understood and readily carried into effect, we shall describe the same in more detail with reference to the accompanying drawing in which,

, 1939, Serial No. 303,290

ovember 10, 1938 .have a width of about of a shaft 3 extending through the end wall 26 of the housing. A compression spring I8 located within slot 25 presses shaft 3 in the direction of arrow 8.

Rotatably mounted at the end of housing It is a cup-shaped metal member or shear plate 2 whose upper end has a central depression or cavity 6 which forms an annular surface provided with a large number of radial or substantially radial slits i. The slits l, which may 0.2 extend'across the annular surface and through the wall 5 of cavity 6 and the outer wall i of member 2. The slits are widened at their ends to guide the hair into the same. Member 2 has an annular flange I 6 which is rotatably secured between the upper edge of housing H and a metal mit I! screwed onto the end of housing I I.

Mounted upon the end of shaft 3 is a cutter t having two cutting edges 8 which are pressed against the inner surface of the annular portionof member 2 by spring 88. As shown in Fig. 3 the cutter i has two diametrically opposite cutting edges, but, we prefer to use three cutting edges located 120 apart because this uniformly distributes the pressure exerted on shaft 3 by spring it. The edges 8 preferably make a sharp angle with the edges of .the slits i.

In accordance with the invention member 2 is rotated at a low speed with respect to the cutter t. For this purpose a gear i 0 fixedly mounted on shaft 3 drives a gear I 2 rotatably mounted on a pin l9 secured to wall 24. The lower end l3 of member 2v is provided with internal teeth engaging the gear l2 and with a flange 20 which serves to support gear l2. As shown more clearlyin Figure 2, member 2 is driven from shaft 3 in a direction opposite to the direction of shaft 3 and cutter t.

In practice the cutter d is rotated at a relatively high speed for instance between about 6,000 and 15,000 revolutions per minute. The

member 2 or shear plate is driven at a speed Fig. 1 is a sectionized side-view of a portion of a razor embodying the invention, and

Fig. 2 is a section along .line 2-2 of Figure 1. Fig. 3 is a section on reduced scale taken along line 3'3 of Figure 1.

The razor illustrated in the drawing comprises a hollow housing H of insulating material such as Bakelite, in which is supported an electric motor l5 having a shaft 23. Shaft 23 has a flattened end which fits into a slot 25 in the end which is much lower and of a quite difierent order of magnitude, for instance between and 120 revolutions about revolutions per minute.

As stated the razor according to the invention gives entirely satisfactory results regardless of how it is moved over the surface to be shaved i. e. whether it is moved vertically,

horizontally or in a circular manner. ,This is probably due to the fact that the relatively slow and continuous rotation of the shear plate 2 per minute and preferably causes the oblique hairs, which grow in various directions, to be caught better and more regu- -:V:.:-lin the slits 1 than its possible with a circular manually movement of a stationary shear plate.

While we have described our invention in connection with a specific example we do not wish to be limited thereto. Various driving mechanisms may be used and the shear plate may be rotated in the same direction as the cutter. Furthermore, the shear plate, cutter and slits may be of various forms and arrangements.

What we claim is:

1. In an electric razor, a shear plate provided with a large number of substantially radiallyextending slits adapted to receive the hair to be cut, a cutter cooperating with said shear plate, means to rotate said cutter at a high speed includinga motor, and means to rotate said shear plate at a speed which is low with respect to the speed of said cutter.

2. In an electric razor, a shear plate provided with a plurality of substantially radially-extending slits adapted to receive the hair to be cut, a cutter cooperating with said shear plate, means to rotate said cutter at a high speed and means to rotate said shear plate at a speed between about it) and 120 revolutions per minute.

3. In an electric razor, a shear plate provided with a large number of substantially radiallyextending slits adapted to receive the hair to be cut, a cutter cooperating with said shear plate, means to rotate said cutter at a high speed including a motor, and means to rotate said shear plate in a direction opposite to thedirection of rotation of the cutter and at a speed of between about 40 and 120 revolutions per minute.

4. In an electric razor, a shear plate provided with a large number of substantially radiallyextending slits adapted to receive the hair to be cut, a. cutter cooperating with said shear plate, means to rotate said cutter at a speed between about 6000 and 12,000 revolutions per minute and means to rotate said shear plate in a direction opposite to the direction of rotation of'the cutter and at a speed 01' between about 40 and 120 revolutions per minute.

5. In an electric razor, a shear plate provided with a large number of substantially radiallyextending slits adapted to receive the hair to be cut, a cutter cooperating with said shear plate, means to rotate said cutter at a high speed including a motor, and means to rotate said shear plate in a direction opposite to the direction of rotation of the cutter including gearing between said motor and the shear plate.

ALEXIS van DAM. ALEXANDRE HOROWITZ. 

